Squiffle

To persuade someone (Usually a parent) to let you get/do something they wouldn't normally allow. Often associated with cuteness.

"I'm going to be trying to squiffle my Dad into letting us get a cat over the next few days"

Or

"Hey, guess what?! I got a pony!!"

"Wow, how'd you manage that?!"

"Well.. lets just say that a certain amount of squiffling went on over the holidays.."